Nuclear energy is worth pursuing, wind and solar are good but have limitations, and the government is putting minuscule amounts of money into energy R&D dollars.

So says software tycoon turned philanthropist Bill Gates, who launchedhis Gates Notes Web site on Wednesday to share his big-picture ideas on big topics. High on his list is energy and environment, an area where he's already taken lots of notes.

In a series of podcasts, Gates sketches out what technologies and policies are likely to lead to the goal of reducing carbon dioxide emissions to zero.

Bill Gates
Microsoft

In a response to a question, he acknowledges that energy and climate change are not well suited for the Bill & Melinda Gates Foundation, which focuses on finding cures to diseases in poor countries. But he does see energy as a terrific area for marketplace innovation.

"The world really needs cheap energy, particularly the poor need cheap energy. And the world needs to not run the experiment of seeing how much heating and what feedback effects of lots of heating generates. That means you want to try every path," he said.

When it comes to what energy technologies make most sense in the years ahead, Gates says he has a conflict of interest. He and former Microsoft chief technology officer, Nathan Myhrvold invested in TerraPower, a Seattle-area nuclear power company that is working on a reactor design that could use the spent fuel from existing nuclear reactors to make electricity for decades.

Nuclear, though, has major barriers that have nothing to do with technology: it's expensive, there are potential fuel shortages, there's a need for safety, it's hard to find a location for a plant, and radioactive material can be stolen by terrorists to make bombs.

"That's a hard path but it's a path that is more fruitful than most people think because innovation stopped in the 1970s," he said. "It's the only thing we have today other than hydrocarbons that provides a lot of power and you could build a lot more of it."

Solar is another area where Gates sees promise for scientific breakthroughs. He singled out the "solar chemical" research of Nate Lewis from Caltech, which aims to capture the energy in sunlight in some chemical form, be it hydrogen or some other liquid fuel. The key advantage to this approach is that it includes storage and doesn't rely on storing electricity in giant batteries, he said.

Existing forms of solar power--photovoltaics, through which electricity is generated form solar cells, and solar thermal, through which heat is used to make electricity--are far more expensive than fossil fuels and lack storage. Wind, meanwhile, is very mature technologically, which means the biggest barriers to broader adoption are adding transmissions lines and bringing down the cost of construction.

The other large-scale solution to cutting emissions, in Gates' view, is carbon capture and storage (CCS), in which the carbon dioxide from burning coal is separated and stored underground. But "it will take a very impressive CCS thing for coal to make sense. We don't know that that can work," he said.

Gates is all for conservation, or being more efficient with energy, but he thinks it shouldn't obscure the need for innovation, which is required to reach zero emissions.

Hitting the books
Gates is an unabashed capitalist but he agrees that on the topic of energy and environment, the governmenthas a very large role to play.

"I'm always for minimizing the role of government wherever you can, but for almost all these large-scale energy things, the government has to come in and decide what kind of experimentation to allow," he said.

Creating ARPA-E, a research agency geared at breakthrough energy technologies, is a good thing but it's a drop in the bucket compared to the magnitude of the task.

"The relative lack of investment in research and development is incredible. It just jumps out as a huge mistake because in the long run to get to zero carbon emissions, it's a case of using technologies that don't exist today, both in generation and the storage space as well. Then you have the transportation sector," he said.

Even though his financial activity in green technologies is relatively limited, it's clear that Gates has been thinking hard about energy and climate. He plans to talk more about energy at the TED conference next month.

"This is such a complex topic, my first call to action is to learn more because the government has a role in this. It's hard to sort through the strong, strong opinions on this one," he said.

About the author

Martin LaMonica is a senior writer covering green tech and cutting-edge technologies. He joined CNET in 2002 to cover enterprise IT and Web development and was previously executive editor of IT publication InfoWorld.
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